ABSTRACT

This is a review of the role of Bacillariophyta in the formation of biofilms, which are microbial communities immersed in a self-produced matrix of sticky mucus into the extracellular space forming a complex of polymeric substances. We discuss the ecological function of biofilms in coastal ecosystems and estuarine areas, and the role of diatom exudates in the ecology of cells, inhabiting marine sediments and being an important source of carbohydrate components. More than half of the organic carbon found at the bottom of the ocean, a significant portion of which are soluble organic compounds that, is a product of Bacillariophyta photosynthesis. Depending on external conditions and motility, diatoms can release substantial amounts of polymeric substances into the environment, mainly exopolysaccharides (EPS). One of the main ecological functions of EPS in aquatic ecosystems is the bio-stabilization of sedimentary material, providing preservation of the structure of the intertidal zones subject to erosion.